表面改性对 Nano-SiO 2表面电位及乳状液稳定性的影响

摘要

使用硅烷偶联剂 KH-550对纳米二氧化硅(Nano-SiO 2)进行表面有机改性。使用 Zetasizer 3000电位仪,系统分析 KH-550的用量、改性时间以及改性温度等因素对 Nano-SiO 2表面ζ电位的影响,得到不同改性条件对Nano-SiO 2表面ζ电位的作用规律,从而建立改性 Nano-SiO 2表面ζ电位与有机改性条件的关系。将改性前后的Nano-SiO 2与石油磺酸盐-PS 复配,得到改性二氧化硅/表面活性剂(KH550-g-Nano-SiO 2-PS)复合体系。采用界面张力仪(TX-500c),系统研究该复合体系降低油/水界面张力能力,并利用 Turbiscan Lab 型乳状液稳定性分析仪,系统研究油/水乳状液的稳定性。结果表明,当石油磺酸盐表面活性剂质量分数为0.5%时,该体系油/水界面张力降低至2.30×10-2 mN/m,然而当 KH550质量分数为5%时,KH550-g-Nano-SiO 2-PS 体系能使油/水界面张力降低至5.42×10-3 mN/m,达到超低界面张力,且乳化液稳定性最大,此时 KH550-g-Nano-SiO 2-PS 体系表面ζ电位为-50.1 mV,通过表面ζ电位的变化分析了油水界面张力变化及乳状液稳定机理。%Nano-silicon dioxide was organic modified with silane coupling agent KH550.The influence of modification conditions on surfaceζ-potential of nano-silicon dioxide was characterized by Zetasizer 3000.The modified nano-silicon dioxide was respectively compounded with petroleum sulfonate.The ability of the composite system for reducing the oil water interfacial tension was measured by interfacial tensiometer TX-500.Turbiscan Lab was applied to analyze the stability of oil-water emulsion.The results showed that petroleum sulfonate system could reduce the oil water interfacial tension to about 2.30 ×10 -2 mN/m,and modified nano-silicon dioxide and petroleum sulfonate composite system could reduce that to about 5.42 × 10 -3 mN/m,when the concentration of surfactant was 0.5% and the modified nano-silicon dioxide surface zeta potential was-50.1 mV.The oil-water interfacial tension change and mechanism of emulsion stability were analyzed through the changes of surface zeta potential of modified nano-silicon dioxide.